I am unable to download my mail using the native mail app after upgrading to IOS 18. I am getting the following error; “Network Error (POSIX 96)”
The mail configuration is on imap with SSL.
iPad Pro, iPadOS 18
@ferrerod:
Here's the main part of the response I got from Fastmail who diagnosed and solved the problem on my account. It seems there was a bug in their mail engine that was benign until the iOS18 update, then no more. I hope this helps.
We had a bug which put random data into the HIGHESTMODSEQ value for some users. Their account was affected by this. We didn't think it was an issue because there was still heaps of number-space left, but the HIGHESTMODSEQ values were higher than a signed int64 can hold. This was fine because we use an unsigned int64_t internally, but the spec was updated a few years ago to make it a signed value, so we were strictly wrong.
Apple's parser couldn't handle these oversize numbers, and failed.
--
This has now been fixed by resetting the HIGHESTMODSEQ value for these users which also means this will never happen for them again.
ferrerod wrote:
Did fastmail tell you what technically they did? No one else has a workable solution. Some of us support our own mail serves - though perhaps rare.... would be great if you could get them to tell you exactly what they did for IMAP solution.
Indeed , when is coming up the fixing upgrade ???
What is the phone number for Apple support?
Same problem here. Now I can send mail but not receive it. I’m very disappointed with Apple.
me , too , I even wonder if Apple ever plans to fix this great bug ???
I am also having the POSIX (96) problem and have been for several weeks. I am VERY tempted to get myself an ANDROID device just so I can access my emails!
Thanks 🙏 and 🤞maybe fixing this problem
We run a mail server, if we would have been able to solve it with a workaround, we would have done this.
Apple needs to fix this
not sure what this has to do with this thread. the accounts and servers that have this issue for me are most certainly using SSL - non encrypted protocols are 100% blocked.
what OS are you running dovecot on? that would help point in the correct directon
Where did you get the "imap_capability" string?
Yes I read that and taking the original string I used with netcat (rather than telnet) without IDLE was one of those strings I tried and failed. I'm trying to revert to iOS 17...wish me luck.
I have also tried remove all certs (including a CA) and reinstalling but nothing has worked. Not really sure what your WIFI would have to do with the issue.
Are you sure you have it working? It worked initially worked and got inbox email and the folders, but then went back to failing.
Clyde - 2.2.30.2 (c0c463e)
Error downloading mail
Error in downloading mail on IMAP after ios 18 upgrade
